1) Field of the Invention
The present invention relates to a latch apparatus for canceling a half closed state or a fully closed state of a door held by a latch mechanism.
2) Description of the Related Art
Conventionally, in a vehicle such as a four-wheel automobile, a latch apparatus provided in a slide door is provided with a latch mechanism, a handle lever and an open lever.
Japanese Patent Application Laid-open No. H6-212844 discloses a latch mechanism that holds a slide door to a vehicle body in a half closed state (a non-completely closed state) or a fully closed state (a completely closed state) through engagement with a striker provided on a side of the vehicle body. The handle lever performs an opening action based on an opening operation of an inside handle provided on an inside panel of the slide door, or an opening operation of an outside handle provided on an outside panel. The open lever performs a door opening action according to a door-opening operation of the handle lever, in an interlocking manner with the latch mechanism and cancels a half closed state or a fully closed state of the slide door that is held by the latch mechanism according to the door-opening operation.
However, in the latch apparatus, an opening action of the handle lever is performed in the following manner. A control unit interposed between the handle lever and the inside handle and the outside handle performs the opening action of the handle lever. The control unit is connected to an inside handle mechanism constituting the inside handle via an inside cable, and is also connected to an outside handle mechanism constituting the outside handle via an outside cable. The control unit is provided with a unit lever that swings via a return spring according to an opening operation of the inside handle, namely, a pulling action of the inside cable performed by the inside handle mechanism, and swings according to an opening operation of the outside handle, namely, a pulling action of the outside cable performed by the outside handle mechanism. The unit lever is always in a standby position due to biasing force of the return spring, but is swung against the biasing force of the return spring by a pulling action of the inside cable or a pulling action of the outside cable. The unit lever is coupled with the handle lever via a unit cable, and the handle lever performs an opening action according to swinging of the unit lever, i.e., a pulling action of the unit cable.
Therefore, for the handle lever to perform an opening action according to an opening operation of the inside handle, not only a pulling action of the inside cable but also a pulling action of the unit cable is required. Similarly, for the handle lever to perform an opening action according to an opening operation of the outside handle, not only a pulling action of the outside cable but also a pulling action of the unit cable is required. That is, for the handle lever to perform an opening action according to each of the opening action of the inside handle and the opening action of the outside handle, it is necessary to swing the unit lever against the biasing force of the return spring. Therefore, in order to cancel the half closed state or the fully closed state of the slide door held by the latch mechanism through the opening action of the handle lever and the door opening action of the open lever conducted by the opening operation of the inside handle and the opening operation of the outside handle, respectively, an excessive operating force is required.